Nanobody-shell functionalized thermosensitive core-crosslinked polymeric micelles for active drug targeting

Area of Science:

• Biomaterials Science
• Nanotechnology
• Oncology

Background:

• Polymeric micelles offer potential for drug delivery due to their size and ability to encapsulate therapeutics.
• Active targeting strategies, such as using antibodies or nanobodies, can improve drug accumulation at tumor sites.
• Epidermal Growth Factor Receptor (EGFR) is frequently overexpressed in various cancers, making it a viable target.

Purpose of the Study:

• To develop core-crosslinked, thermosensitive, biodegradable polymeric micelles decorated with an anti-EGFR nanobody (EGa1) for active tumor targeting.
• To functionalize poly(ethylene glycol)-b-poly[N-(2-hydroxypropyl) methacrylamide-lactate] (mPEG-b-p(HPMAm-Lac(n))) block copolymers for micelle formation and nanobody conjugation.
• To evaluate the targeting efficacy and specificity of the EGa1-conjugated micelles towards EGFR-overexpressing cancer cells.

Main Methods:

• Synthesis of a functionalized block copolymer (PDP-PEG-b-p(HPMAm-Lac(n))) for micelle formation.
• Preparation of core-crosslinked micelles and conjugation of the EGa1 nanobody via a disulfide linkage.
• Characterization of micelle conjugates using SDS-PAGE, GPC, western blot, and dot blot analysis.
• In vitro evaluation of micelle binding and cellular uptake in EGFR-positive and EGFR-negative cancer cell lines.

Main Results:

• Successful synthesis and characterization of EGa1-conjugated polymeric micelles.
• EGa1-micelles demonstrated significantly enhanced binding and uptake by EGFR-overexpressing cancer cells (A431, UM-SCC-14C) compared to untargeted micelles.
• Specific binding was confirmed by the lack of interaction with EGFR-negative cells (3T3) and competitive inhibition studies.

Conclusions:

• EGa1-decorated (mPEG/PDP-PEG)-b-(pHPMAm-Lac(n)) polymeric micelles are effective for active tumor targeting.
• These targeted micelles show high specificity for cancer cells overexpressing EGFR.
• The developed system holds significant promise for advanced cancer drug delivery applications.